The invention relates to a drainage device for treating wounds using a reduced pressure, comprising:
a gas-tight wound-covering element, which consists of a sheet-like material and, when placed in contact with the body of the patient, is fastened adhesively to the surface of the skin about the region of the wound, forming a sealed, wound space remaining between the respective wound and the wound-covering element, and at least one drainage tube, which can be connected to a means, such as a vacuum pump, for producing the reduced pressure and can be inserted prone into the wound space approximately parallel to the wound-covering element and over which the materials in the wound space can be evacuated,and at least one absorption body, which is disposed in the wound space and absorbs the wound secretions.
A device of the type named above is known from the DE 195 17 699. The known device has a covering sheet for covering the wound flat and closing it off air-tight, so that a wound space, into which an insert of a foam material and a drainage hose, which is pulled into this insert, are inserted, is formed underneath the covering sheet in the region of the wound. With the help of the insert of foam material, the wound secretions are to be withdrawn uniformly over the whole of the wound surface. A collecting container with a vacuum pump for producing the reduced pressure is, in turn, connected to the drainage tube. The whole device is disposed of when the collecting container is filled with wound secretion. The purpose of the disposable device is to pass the wound secretions continuously through the drainage tube into the collecting container.
U.S. Pat. No. 5,549,584 shows a device for vacuum treatments, which consists of a wound cover, a membrane pump, which is disposed at the suction tube, and a pouch-like collector, which is connected downstream from the membrane pump. A layer of material or a loose bed of liquid-absorbing fibers, which rest on a perforated layer and under which a further adhesive layer, in turn, is placed, is disposed underneath the wound covering. Furthermore, the fibers are covered by a liquid-permeable upper layer, which has several windows. Beneath each window, there is a section of material, which is also permeable to liquids. The suction tube is connected with a connecting piece, which is disposed above the wound cover, and does not have any direct contact with the absorption material, which is located within the wound space. The device, so designed, seems complicated and expensive to produce.
The DE 29 53 373 C2 also discloses a device, which uses reduced pressure for the treatment of wounds and comprises a wound-covering element, a foam material insert underneath the wound-covering element and at least one flexible conduit, which communicates with the pores of the foam material insert. In the DE 38 50 798 T2, a sterile, rectangular, yet rigid cassette, in which a surgical dressing is accommodated, is shown. The lower edge of the cassette is fastened to the skin of the patient. For enclosing the surgical field at the patient, the cassette is open at the top and at the bottom.
U.S. Pat. No. 5,086,763 A discloses a cassette-like wound-treating device, which is also fastened to the skin of the patient. An exchangeable wound dressing is placed at the underside of a swiveling lid.
A pouch-like wound-treating and wound drainage device, known from AT E33 446 B, has a lower, peripheral edge, by which it may be glued to the skin of a patient, a catheter holder, two treatment openings with caps, which are disposed at an upper wall, as well as an opening at the lower wall of the pouch for enabling access to the wound. The publication describes only the construction of the pouch.